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New to the group and experiencing a problem


Joe
 

On 4/25/2020 8:56 AM, Terry Y wrote:
I'm still working on the analyzer problem.  The SWR reading are in the 3.0:1 range on all bands when I connected directly to the antenna.  So I'm still looking for information about the effect on any effort to analyze the SWR through the AH-4.
After tuning with the IC-7000 are you leaving power on the radio when you disconnect the tuner and connect the analyzer?  I would imagine that you should be doing this to keep the tuner powered up. If you are using the standard ICOM cable the tuner gets the power from the radio.

You might find some of the information here interesting.

<https://wp.hamoperator.com/?page_id=1043>

<https://hamoperator.com/HF/AH-4_Design_and_Operation.pdf>

73, Joe, K1ike


Terry Y
 

J.D.,

Yeap, I'm still here, just outside working the problem.  The counterpoise is in the antenna manufacturer's recommended range of 50' to 55'.

Can you explain in more detail what you mean by the AH-4 replacing the antenna loading coil?  I wish, back in the early 1970's when I learned basic electronics and communications concepts, that learned more, or remembered more about antenna transmission and propagation.


Thanks,
Terry, n0ve


 

Terry,
The loading coil is superfluous if you have a tuner like the AH-4 that can be mounted directly at the base. In the case of the loading coil it has losses and does not radiate much if any and it's function can be completely replaced by the AH-4 and then you only have the losses in the tuner instead of the losses for the tuner and the loading coil.
The tuner will automatically add the necessary inductive or capacitive reactance to present a 50 Ohm load to the transmission line and the transceiver. The only real problem might be if you have a bad connection on the coax or a bad coax. Try the suggested dummy load at the coax end at the tuner and check with your analyzer to see if you have a 1:1 SWR at 50 ohms then. 
That would be the starting point.
After proving that the coax was OK try adding the AH-4 with the dummy load between the antenna and ground connection and it should tune and also present a 50 ohm load to the transceiver or analyzer. The AH-4 should make a straight pass through connection when powered off (I think I remember correctly).
When you have proven that the above is correct then just connect the antenna wire to the antenna out on the AH-4 and the ground to a ground stake (the counterpoise can be connected as well to serve as a ground return radial and reduce ground losses. More are better. This will basically give you a longwire antenna which in my estimation is just as good as any other given that the wire is the radiator and the rest of the "stuff" exists just to match the coax better. 
The basic setup for this antenna is to give a close enough match to use an indoor tuner or no tuner, but the SWR can cause more losses in the coax than they save in the long run.
Let me know what you find.

DE KE4MD


Chuck Scott <cscott@...>
 

All:

One thing to remember about the AH-4 is that it always presents a low SWR to the radio while it's tuning, so you can't use that as an indication for how well it's doing. After tuning, if it found a solution, the SWR the radio sees is with the solution the AH-4 found.

This is also why you should always tune the AH-4 with reduced power to protect the pad it puts in the line, which the Icom radios seem to do. If you adapted the tuner to another type of radio you may have to reduce the power manually.

Chuck - N8DNX


Terry Y
 

Hi Al,

I install Anderson Powerpole connectors on any 12VDC connector that comes into my possession.  So, I reseated the Powerpole connectors at the back of my radio that goes to my power source.  That power source includes a West Mountain Rigrunner 4004U, West Mountain PWRgate 40S, a deep cycle Marine AGM battery, and a Samlex SEC1223 regulated power supply.  

Initially the 7000 power was set to 100% because I participate in a NTS net with stations from Colorado, Utah, Arizona, Washington, and California.  As part of my troubleshooting I wondered if the 7000 at 22 amps output was too much for the SEC 1223 which is rated at 23 amps, so I reduced the 7000 to 75% power out (changed radio settings not by measurement).  No change.  Then I reseated the Powerpole connector at the back of the radio to the Rigrunner 4004U.  Then I reseated all the Powerpole connectors and the 7000 has since failed again; the connectors were not the problem.  

After additional troubleshooting, I am inclined to believe the battery, which is about a 2014 vintage, is my problem.  I bypassed the PWRgate 40S (the battery connects to and provides the 12VDC to the Rigrunner 4004U where the radio is plugged into) and I have not had a failure since.

This is a longer answer then you were looking for, but it's for the benefit of everyone following this thread and especially those that have conributed suggestions.

Good luck with your power reduction problem.

Terry, n0ve


Tony
 

Hi
I use the 7000 and AH4 and experience the power regularly if SWR is high. The 7000 is designed that way to protect the rig.
Testing on dummy load will confirm this.
Remember the AH4 will not tune everything. The antenna has to be nearly matched at least before the AH4 can do its work
Regards
Tony
MW0TRO


N3EA
 

Hi Terry,

Thanks for the info. Your setup is pretty much how the setup is here at the CERT station that we have at our HOA clubhouse except we have a different power supply. So far, no problems with that one. The 7000 I have in the car is just connected directly to the vehicle battery with the two automotive type fuses in line located right near the battery. So, the only places that might have started to oxidize would be at the connector on the back of the rig or in the fuse holders. I haven't had a chance to look into it yet. BTW..I use a Samlex SEC-1223 at my station at home and it's been very reliable for a long time. I've even taken on a couple of holiday style DXpeditions because it's not too heavy to carry around.

73,

Al, N3EA